Wiedząc ze a) sin α = 1213 b) cos α= 13       Oblicz wartosc pozostałych funkcji kąta α            oznacza kreske ułamkowa

a) sin a = 12/13      sin^2 a + cos^2 a = 1      cos^ a = 1 - sin^2 a = 1 -(12/13)^2 = 1-144/169 = 25/169 cos a = 5/13 tg a = sin a/cos a = 12/13/5/13  tg a = 2,4 ctg a = cos a/sin a = 5/13/12/13  ctg a = 5/12 b) cos a = 1/3         sin^2 a = 1 - cos2 a = 1 -(1/3)^2 = 1-1/9 = 8/9 sin a = 2V2/3 tg a = sin a/cos a = 2V2/3/1/3  tg a = 2V2 ctg a = cos a/sin a = 1/3/2V2/3 = 1/3 * 3/2V2 = 1/2V2 * V2/V2  ctg a = V2/4